Since you are using asp.net, interop is not an option. Microsoft has an OpenXML SDK, with plenty of samples here:
http://msdn.microsoft.com/en-us/library/cc850833.aspx[
^], but as I see it won't work with c# 2.0.
As OpenXML is an open format, you could make your own code to to the manipulation directly on the XML. You could probably find some third party libraries also, that might work with c# 2.0. But: why c# 2.0? If you have to deal with Word 2007 or above, you need to have at least .net 3.5 installed... so I suggest you forget c# 2.0 as soon as possible.